14-year old girls in the 1940's and 50's played hopscotch and skipping rope, teenage boys (even as old as 16) climbed trees, swam in lakes and built model planes, ships etc.
Teens playing? playing is for children. Also they ate all kinds if crap in diners like burgers and milkshakes (why...
He said that during WW2 the Japanese planned an invasion of the United States through the West coast but abandoned all plans because they knew the majority of Americans would be armed.